They are typically worth around £3,000 to £5,000 - which is more than the cost of many of the holidays involved.

In cases where tour operators make a payout, they can attempt to claw the money back from the hotels themselves.

Tui’s managing director Nick Longman told the Press Association that there had been ‘friction’ between hotels and tour operators.

He said: ‘There’s a distinct risk that if this carries on as it is unabated, the hoteliers will say to us either “We don’t want to work with the British market at all” or “We’re not going to offer you all-inclusive”.

‘I think that would be a terrible thing for the British customer. It’s just going to reduce the choice in terms of destinations and the type of holiday.’

Abta chief executive Mark Tanzer said the fraud is ‘one of the biggest issues that has hit the travel industry for many years’.